I also read about this a while ago. Sick fuck :/.. or sick fucks is probably the right term, as that boy/man is just sitting there doing nothing.. no matter how outnumbered I'd be, I would still do something if I saw a guy beating a girl. I'd much rather prefer that it's me getting beat up than the 16 year-old girl sitting in front of me.
Damn, stuff like this really makes me feel depressed. And at the sime time pissed
EDIT: And GlennMirnyi, what the hell is your problem? You honestly think being afraid is an excuse for doing nothing? I'm sure I'd be shocked as well, and maybe even afraid.. but that shouldn't stop anyone who actually CARES from interfering. I mean c'mon.. it's a girl. And youre a guy. It should be obvious how you react.